Domical structure

ABSTRACT

A domical structure employing beams having given cross-sectional configurations providing interlocking connections between main and tertiary beams of the structure whereby the beams are held together by a wedging and/or supporting action utilizing the effects of gravity.

United States Patent [1 1 Sumner [4 Apr. 9, 1974 [54] DOMICAL STRUCTURE 3,635,509 1/1972 Birkemeier 52/81 [76] Inventor: John S. Sumner, 728 N. Sawtelle OTHER PUBLICATIONS 85116 Architectural Record Feb. 1960 pages 226-230 copy 22 Filed: Jan. 5, 1973 in Design Library [21] Appl' 321515 Primary Examiner-John E. Murtagh Attorney, Agent, or Firm-Warren F. B. Lindsley [52] U.S. Cl. 52/80, 52/86 [51] Int. Cl E04b1/32 7 ABSTRACT [58] Field of Search 52/DIG. 10, 80, 81, 648,

' 52/86 665 A domical structure employing beams having given Y cross-sectional configurations providing interlocking [56] References Cited connections between main and tertiary beams of the structure whereby the beams are held together by a UNITED STATES PATENTS wedging and/or supporting action utilizing the effects 2,716,993 9/1955 Codrick 52/81 f gravity. 3,284,970 11/]966 Stowasser.... 52/80 3,462,893 8/1969 Kaiser Dl3/l E 7 Claims, 12 Drawing Figures PATENTEI] APR 9 I974 SHEET 3 0F 3 lEll-l -11 1 DOMICAL STRUCTURE BACKGROUND OF THE INVENTION This invention relates to the construction of domical bets.

structures and moreparticularly to a simple and more secure assembly and erection of the framework of such a structure using laminated and/or solid beams with interfitting connections to insure strong joints of perfect fit and maximum carrying capacities. The connections between the. beams of the structure utilize the actual stresses acting between the beams to assist in holding them together, thereby minimizing use of metal fastening plates, bolts and the like.

FIELD OF THE INVENTION Another object of this invention is to provide a domical structure wherein the beam members have crosssectional configurations adapted to interlock with intersecting members without mortise-and-tenon cuts therein.

This invention is particularly directed to the con- I structional features of domical structures wherein the cross-sectional shape of, for example,' laminated woodenbeams is such that a secure interlocking of the beams maybe obtained at abutting joints without the need for mortiseand-tenon connections and with a minimum of fasteners to hold the connections together.

DESCRIPTION OF THE PRIOR ART of material used. Domes also have the highest strength per weight of any natural or man-made structure. In addition, they arethe most stable building enclosure devised, sinceforce applied at any point is absorbed proportionally by all frame members. I

However, domical structures have not gainedwide acceptance in spite of these many advantages. One of the reasons for the lack of acceptance is the difficulties encountered in fabricating and erecting such astructure. Most. domical structures have complicated joint connections which are not easily assembled in the field, and. the beam members used have been difficult to form and install. In the past, beams supporting domical structures have been fastened together by means of metallic plates, bolts, pegs, screws, and nails, which fasteners have been subject to the stress loads. These fasteners must also provide the necessary joint strengthfor such structures because conventional joints between adjoining beamshave been inherently weak.

SUMMARY OF THE INVENTION In accordance with the invention claimed, a domical structure is disclosed which overcomes the difficulties encountered in the forming and erecting of such structures. The claimed configuration provides a strong, low cost, easy to erect and efficient domical structure for use, inter alia, for domestic, commercial, and military purposes.

This invention employs a superior method of abutting Another object of this invention is to provide a domical structure wherein the interconnecting members are assisted by their shape and gravity to remain in position.

Another object of this invention is to provide a domical structure which embraces all of the advantages of great strength, minimum amount of materials, low cost, an efficiency, yet is simple to construct and erect.

These and other objects and advantages of this invention will become more apparent as the description proceeds, and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be more readily described by reference to the accompanying drawings of which:

FIG. 4 is.an enlarged fragmentai view of a base and fabricated metal mount for the ends of the primary and.

secondary beamsof thedomical structure shownin FIGS". 1 and 2.

FIG. 5 is a sideelevational view of FIG. 4.

FIG. 6 is an enlarged top plan view of the center part of the dome showing the connection of theprimary beams atthe point they intersect and join.

FIG. 7 is a sectional view on the line 7-7 of FIG. 6.

FIG. 8 isa view similar to FIG. 2 with tertiarybeams installed. 1 I

FIG. 9 is an enlarged top plan view of the joint between primary or secondary beams and the tertiary beams of the structure shown in FIGS. 1-8.

FIGS. 10, 11 and 12 are cross-sectional views of some of the various shapes of primary and secondary beams which may be employed in my structure which show how the tertiary beams butt joint in a perfect fit without weakening the primary or secondary beams.

DESCRIPTIONOF THE PREFERRED EMBODIMENT Referring more particularly to the drawings by characters of reference, FIGS. 1--3 disclose a framework for a domical structure 10. having a base or mounting pad 1 l for each of the comers of the domical structure.

The base may comprise any suitable solid mount, such 7 as the concrete pier shown, which may extend into the ground 12 a suitable distance to provide sufficient bearing and stability for the structure. The base may also be a steel beam or wooden post or any other suitable base member installed in the ground. Steel rods not shown may extend between the piers to anchor the domical structure.

It is to be noted that the base 11 may be of any suitable height above the ground, that is, they may extend only slightly above grade, or they may extend a foot or even several feet above ground to set the domical structure at any suitable elevation relative to the grade or ground level.

FIGS. 1-3 illustrate three bases 11 arranged at the corners of an equilateral triangle, although it is deemed apparent that four, five, or even more bases may be used for various styles or sized domical structures without departing from the spirit of this invention.

Each base 1 1 has an anchor bolt or bolts 13 inbedded therein and extending upwardly therefrom. A simplified beam mounting bracket 14 is mounted on the base embracing the anchor bolt and is secured to each of the bases by nut 15 which firmly clamps the brackets to their respective bases as shown more clearly in FIGS. 4 and 5.

Each of the brackets 14 is triangularly shaped in plan view and is bent upwardly to extend inwardly and upwardly toward the center of the domical structure for receiving and holding the ends of primary beams 16 and secondary beams 17.

As clearly shown in FIGS. 4 and 5, the ends of the beams 16 and 17 are secured to brackets 14 by means of an elongated bolt 18 which extends through each of the beams 16 and 17 adjacent to their .ends, and through bent-up ears 19 formed integral with or welded to bracket 14. Spacers 20, 20 are provided on the elongated bolt 18 to hold the primary and secondary beams in their desired relationship to each other. As shown, the primary beam 16 is in the middle with the secondary beams 17-17 on each side within bracket 14.

As evident from the drawings, the mounting of the primary and secondary beams is similar at each support location for the building. The structure illustrated in FIGS. 1-3 is supported on three bases, although it is deemed apparent that more than three points of support may be employed if so desired.

As shown in the drawings, the primary and secondary. beams may be laminated. These laminated beams are preferably fabricated in an arcuate form, that is, they are glued together in the arcuate or contour shape desired for maximum strength and minimum weight. They also insure the contour of the domical structure desired. The laminations are disposed in parallel relation to the bottom face of the beam, and to the direction-of arch, so that the stresses of gravity and those applied to the dome act substantially perpendicular to the lame]- lae.

As shown in FIGS. 1 and 3, the secondary beams l7-l7 are arcuately shaped with common ends mounted on one of the brackets 14--14. These beams form an arch between two adjacent bases 11, and for the sake of structural efficiency, they are leaned or inclined from the perpendicular at any suitable angle to give support to the ends of the primary beams and to provide desired ground clearance at the apex of the arch. These secondary beams define or comprise the perimeter of the domical structure.

The primary beams l6--16 are carried in the middle of bracket 14, that is, between the secondary beams 17-17, and are preferably in a plane which is perpendicularly disposed relative to ground 12 and extend over the center of the domical structure.

All of the primary beams 16-16 intersect at the center 21 of the dome and are connected together at this point. As shown in FIG. 6, the abutting ends of the primary beams 16-16 may be cut to matching wedge or pointed shapes 22 to fit together and interlock in a secure firm fit. A steel fastening plate 23 is employed on the under face of center 21 of the dome, and fasteners, such as lag screws or bolts 24-24, are secured through plate 23 into the ends of the primary beams to hold the beams in place. It is deemed apparent that this connection could be made by other suitable means not shown without departing from the spirit of the invention.

The primary beams in the triangularly based domical structure here shown extend beyond the center 21 of the dome and butt against the center or apex 25 of the secondary beams and are secured to the secondary beam in any suitable manner. The particular structure of the butt joint is important to this invention and will be described in more detail later in the specification.

Although not shown in the drawings, it is deemed apparent that if an even number, such as four, bases 11 were used in building a structure employing my invention, each of the primary beams 16 would extend between or be carried on two ends by the brackets 14 and that the primary beams 16 would extend between opposite bases 1 l, and all primary beams would meet and join at the center or apex 21 of the dome.

As stated above, each of the primary and secondary beams 16 and 17 may be homogeneous, i.e., of uniform composition throughout or fabricated in arcuate form from laminated wood, metal, or other suitable material. As can be seen clearly in the drawings, beam 16 has a special cross-sectional shape, the preferred form being trapezoidal, as shown in FIGS. 1 through 10. Alternate cross-sectional shapes are shown in FIGS. 11 and 12. These shapes have been chosen to accomplish a secure keystone-type connection at the juncture or joint between structural members of the dome and to utilize the actual stresses acting between the beams to assist in holding them together whereby the supplemental use of steel fastening plates, bolts, etc., is minimized.

The cross-sectional shapes of beams 16 and 17 all provide an upwardly disposed area or sloping surface capable of supporting 'in place one end of a tertiary beam 26 thereon.

While an inverted triangular cross-sectional shape is optimum for the conventional keystone of a doorway arch used in solid structures, the opposite, or noninverted, triangular shape is the best cross-sectional beam shape for a wooden beam for supporting a structural surface. Thus, in cross-section, the preferred beam structure of this invention has an erect, truncate, triangular shape (see FIG. 10) with a flat, outwardbearing surface 28 to receive the overlying or surface covering material, not shown, of the domical shaped building. This beam shape A-B also allows a simple interlocking keystone joint 29 between beams, such as those shown in FIGS. 3 and 8 through 10, by shaping or cutting the end C of the abutting beam D to fit the contour or shape of the face A of the beam E against which it is engaged.

As shown in the drawings, this interlocking keystone joint is used primarily in the installation of the tertiary beams 26 in the domical structure.

In FIG. 8, a plurality of tertiary beams 26 are shown installed utilizing the interlocking keystone joint. As can be readily'seen from the drawings, this keystone joint results in a firm fit of the adjoining beam members with no weakening of any member because mortiseand-tenon joints are not required, and a minimum of fasteners is required. A simple steel backing plate 27 with a fewlag screws or bolts 24, as shown in FIG. 9, is all that is required to hold the connection together. Stresses applied to the structure are transmitted through the large abutting areas of the beam ends into their adjoining members as in a masonry keystone joint. As is well known in domical structures, forces applied to the dome are distributed proportionally throughout the members of the structure, thus the fitted keystone joint performs admirably in a domical structure.

As shown in the drawing FIG. 3, at each of the connections where a primary beam 16 abutts and joins a secondary beam 17, a keystone joint isemployed. The fitted connection results in a firm structural connection.

The number of tertiary beams 17 used in any domical structure employing my invention will-obviously depend on the size of the structure being built and the loads on the dome expected to be encountered during its use. These factors will also determine the crosssectional area of the primary, secondary and tertiary beams, as is well known in the art.

FIG. 11 discloses a modification of the triangular cross-sectional configuration of the adjoining beams 16 and 17 shown in FIGS. lwherein a primary beam 30 made of wood or metal provided with an inverted T-shape interlocks with an adjoining tertiary beam 31. As shown, the adjoining beam is provided with a surface 32 which ,interlocks with the inverted T-shaped cross-sectional configuration of the primary beam 30.

FIG. 12 illustrates a further modification of the structure shown in FIGS. ll1 wherein the primary heam33 made of woodor metal is provided'with a horizontally positioned H-shapcd configuration and the tertiary beam 34 is provided with an end 35 having an end 36 which fits snugly between the legs 37 of the H-shaped configuration of primary beam. 33, as shown.

it is deemed apparent from the above, that I have provided an improved concept in domical structures which will result in lower cost, easier erection, and stronger beam connections while maintaining all of the advantages heretofore known in such structures. It will be apparent to those skilled in the art that changes and other modifications may be made to the structure shown and described herein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is:

l. A domical structure comprising:

a plurality of bases, 7 a

a plurality of integrally preformed arcuately shaped primary beams carried on at least one end by said bases and extending therefrom in a substantially vertical plane;

a means for connecting said primary beams at apex of said structure,

said primary beams having cooperating trapezoidal shapes providing outwardly disposed support areas,

the

said cooperating support areas of said primary and tertiary beams form a keystone or gravity supported connection.

3. The domical structure set forth in claim 1 in further combination with:

a plurality of arcuately shaped secondarybeams having their ends supported on adjacent bases and extending therebetween to define the perimeter of said structure.

4. The domical structure set forth in claim 1 wherein:

said primary beams are formed at least in part of laminated. materials.

5. The domical structure set forth in claim, 1 wherein said primary and secondary beams are formed at least in part. of laminations of wood.

6. The domical structure set forth in claim 1 in further combination with:

a plate member fastened to the underside of at least some of their. intersections with'other beams to secure said connection.

7. In a domical structure mounted on a horizontal surface and having a plurality of arcuately shaped primary beams supported at their ends from spaced base members and intersecting at the apex of a dome and a plurality of arcuate secondary beams commonly supported on said base members and defining the perimeter of said structure,'the improvement comprising:

said primary beams having cooperating shapes providing outwardly and upwardly disposed support surfaces,

and a plurality of straight tertiary beams engaged between and in angular relationship to said primary and secondary beams to form said domical shape,

said tertiary beams having their ends shaped to the contour of said cooperating support surfaces of said primary beams and said secondary beams against which they engage to provide a connection between primary and secondary beams to rigidify said structure and to utilize the effects of gravity to keep the primary, secondary and tertiary beams together. 

1. A domical structure comprising: a plurality of bases, a plurality of integrally preformed arcuately shaped primary beams carried on at least one end by said bases and extending therefrom in a substantially vertical plane, a means for connecting said primary beams at the apex of said structure, said primary beams having cooperating trapezoidal shapes providing outwardly disposed support areas, and a plurality of tertiary beams mounted between said primary beams to interconnect said beams in a domical shape, said tertiary beams having their ends shaped to the contour of the cooperating support areas of said primary beams to form an interlocking connection for said tertiary beams to said primary beams to rigidify and to cause gravity to aid in keeping said primary and tertiary beams together in said domical structure.
 2. The domical structure set forth in claim 1 wherein: said cooperating support areas of said primary and tertiary beams form a keystone or gravity supported connection.
 3. The domical structure set forth in claim 1 in further combination with: a plurality of arcuately shaped secondary beams having their ends supported on adjacent bases and extending therebetween to define the perimeter of said structure.
 4. The domical structure set forth in claim 1 wherein: said primary beams are formed at least in part of laminated materials.
 5. The domical structure set forth in claim 1 wherein said primary and secondary beams are formed at least in part of laminations of wood.
 6. The domical structure set forth in claim 1 in further combination with: a plate member fastened to the under side of at least some of their intersections with other beams to secure said connection.
 7. In a domical structure mounted on a horizontal surface and having a plurality of arcuately shaped primary beams supported at their ends from spaced base members and intersecting at the apex of a dome and a plurality of arcuate secondary beams commonly supported on said base members and defining the perimeter of said structure, the improvement comprising: said primary beams having cooperating shapes providing outwardly and upwardly disposed support surfaces, and a plurality of straight tertiary beams engaged between and in angular relationship to said primary and secondary beams to form said domical shape, said tertiary beams having their ends shaped to the contour of said cooperating support surfaces of said primary beams and said secondary beams against which they engage to provide a connection between primary and secondary beams to rigidify said structure and to utilize the effects of gravity to keep the primary, secondary and tertiary beams together. 